Rep. Martha McSally took off into Arizona’s wide-open Senate race on Friday and immediately flew to the front of the formation.

There is, however, one vote the former fighter pilot is – and likely should be – chasing harder than all others.

A new statewide poll of likely voters in the Republican primary gives McSally nearly 31 percent of the vote, to Joe Arpaio’s 22 percent. Kelli Ward dropped to 19 percent.

McSally, I’m sure, has already thanked the political stars that aligned in her favor the minute Arpaio jumped into the race, just days before her own announcement. Should they both stay in, Arpaio and Ward split the hard-right vote, leaving McSally to scoop up everybody else.

McSally out-ranks Arpaio, on Arpaio's turf

Here’s the really bad news for Arpaio.

McSally, a southern Arizona congresswoman, outpolled Arpaio even on his home turf, voter-rich Maricopa County, where 62 of likely primary voters reside. According to the Data Orbital poll, McSally snagged 28 percent of likely primary voters in the state's largest county while Arpaio and Ward were in a statistical dead heat, at just under 22 percent and 20 percent respectively.

The live poll of 500 likely voters in Arizona’s Republican primary was conducted Jan. 11-15 and has a margin of error of 4.38 percent.

“With a little more than eight months to go, this race is long from over but Congresswoman McSally seems to be out of the gate as an early leader,” said Data Orbital pollster George Khalaf.

A reason that Arpaio – who lost his last race for sheriff but endorsed Trump early on, campaigned for him and snagged a pardon for his own criminal conviction – seems to think he has a shot.

Then there is McSally, who didn’t endorse Trump in 2016, criticized some of his early moves as president and tried to distance herself from him last spring.

“There’s just an element out there that’s just, like, so against the president. Like they just can’t see straight. And all of a sudden on January 20, I’m like his twin sister,” she told the Arizona Bankers Association, according to a secretly taped audio of the May speech. “I’m, like, responsible for everything he does, and tweets and says.”

That’s because a Trump endorsement in Arizona is like gold – or maybe even a guarantee of a primary win.

Trump has a tough decision to make

Seventy four percent of likely GOP primary voters have a favorable view of Trump – nearly 55 percent of them strongly favorable, according to the Data Orbital poll.

"A Trump endorsement would go a long way, Khalaf told me. "The President is still extremely popular with GOP primary voters so him weighing in would cause movement in the race for sure."

It seems a given that Trump won’t endorse Ward. If he was going to, he would have already done it. Given that she now carries the taint of Steve Bannon, it’s difficult to imagine Trump rushing to her side.

That leaves Trump with a tough decision.

Does he go with loyalty and endorse Arpaio, the guy who has been there for him since the beginning?

Or does he go with reality and endorse McSally, the congresswoman who is backed by the Senate Majority Leader Mitch McConnell and the GOP establishment? The one who wasn’t there for Trump at the beginning but stands the best chance of beating Democratic Rep. Kyrsten Sinema in the general election?

Will he be governed by his heart and go for Arpaio? Or by his ego -- remember Alabama, where not one but two Trump-endorsed candidates lost -- and go with McSally?

Stay tuned Arizona, the vote that may well most count in Arizona's primary election could be coming from the Oval Office.